Micro heat transfer arrays, micro cold plates, and thermal management systems for cooling semiconductor devices, and methods for using and making such arrays, plates, and systems

Abstract

Embodiments of the present invention are directed to heat transfer arrays, cold plates including heat transfer arrays along with inlets and outlets, and thermal management systems including cold-plates, pumps and heat exchangers. These devices and systems may be used to provide cooling of semiconductor devices and particularly such devices that produce high heat concentrations. The heat transfer arrays may include microjets, microchannels, fins, and even integrated microjets and fins.

We claim: 
     
       1. A method of cooling a semiconductor device, comprising:
 (a) providing at least one heat transfer array, comprising a plurality of stacked and adhered layers comprising at least one metal wherein each of the at least one heat transfer array comprises a plurality of microjet structures; 
 (b) placing the heat transfer array in physical contact with or in proximity to the semiconductor device to be cooled to form a primary heat transfer region having at least one cooling fluid impingement surface; 
 (c) pumping a cooling fluid into at least one inlet of the heat transfer array such that the cooling fluid is jetted onto the impingement surface to extract heat therefrom, then passing the heated cooling fluid to at least one outlet of the heat transfer array, while continuing to extract heat from the heat transfer array, and then onto a heat exchanger where heat is removed from the cooling fluid to produce cooled cooling fluid; and 
 (d) circulating the cooled cooling fluid from the heat exchanger back into the at least one inlet of the heat transfer array to repeat a flow cycle to draw heat from the at least one semiconductor device, 
 wherein the plurality of microjet structures function as fins that contact the at least one cooling fluid impingement surface whereby a lowest portion of the plurality of microjet structures are in solid-to-solid contact with the at least one cooling fluid impingement surface while at least one opening exists in the jetting structures above the at least one cooling fluid impingement surface so that jetted fluid is free from enclosing jetting channels within the microjet structures to impinge on the at least one cooling fluid impingement surface. 
 
     
     
       2. The method of  claim 1  wherein the heat transfer array is configured to use a heat transfer fluid that is a liquid. 
     
     
       3. The method of  claim 2  wherein the liquid comprises water. 
     
     
       4. The method of  claim 2  wherein the liquid does not undergo a phase change during a process of cooling a semiconductor. 
     
     
       5. A thermal management system for a semiconductor device comprising:
 (1) at least one micro cold plate, comprising:
 (a) at least one fluid inlet header or manifold; 
 (b) at least one fluid outlet header or manifold; 
 (c) a hybrid microjet and microchannel heat transfer array, comprising:
 (I) a plurality of microjet structures for directing a heat transfer fluid from the at least one fluid inlet header or manifold onto at least one surface of a primary heat exchange region selected from the group consisting of:
 a. a surface of a heat source or a plurality of separated surfaces of a heat source; 
 b. at least one surface in proximity to one or more heat source surfaces wherein a separation distance between the at least one surface onto which jetting occurs and a surface or a plurality of separate surfaces of a heat source is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um; 
 c. at least one surface of a solid material separated from a surface or a plurality of separate surfaces of a heat source by a gap that is occupied by at least one highly conductive transfer material that may be a different solid, a semi-liquid, or a liquid wherein a thickness of the gap is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um); and 
 d. at least one surface of a solid that is in intimate contact with a surface or a plurality of separate surfaces of a heat source; and 
 
 (II) a plurality of post jetting microchannel flow paths to direct the heat transfer fluid from the primary heat exchange region to the at least one outlet header or manifold, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the microchannel flow paths; 
 
 
 (2) at least one flow path to move heated fluid, directly or indirectly, from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; 
 (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and 
 (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate, 
 wherein the heat transfer array is configured to withdraw heat from a semiconductor device, and 
 wherein the plurality of microjet structures function as fins that contact the at least one surface of the at least one primary heat exchange region whereby lowest portions of the plurality of microjet structures are in solid-to-solid contact with the at least one surface of the primary heat exchange region while at least one opening exists in each jetting structure above the at least one surface of the primary heat exchange region such that fluid can be jetted free from enclosing jetting channels within the microjet structures to impinge on the at least one surface of the primary heat exchange region. 
 
     
     
       6. The system of  claim 5  wherein the at least one surface of the primary heat exchange region comprises a plurality of jetting well surfaces with each jetting well surface surrounded by walls that direct fluid away from the jetting well surfaces into the microchannel flow paths. 
     
     
       7. The system of  claim 6  wherein each of the plurality of jetting well surfaces is configured to directly receive jetted fluid from a single microjet structure. 
     
     
       8. The system of  claim 7  wherein the microchannels direct fluid received from the jetting structures along paths that flow past outside walls of the microjet structures initially in a direction that is substantially anti-parallel to the direction of jetting and then in a direction that is substantially perpendicular to the direction of jetting. 
     
     
       9. The system of  claim 7  wherein the at least one fluid inlet header or manifold is spaced further from the at least one surface of the primary heat exchange region than does a flow path through the microchannels after the fluid leaves the jetting wells. 
     
     
       10. The system of  claim 5  wherein the device comprises a component selected from the group consisting of: (1) an IC; (2) a microprocessor; (3) an SOC; (4) an RFIC, e.g. an RF transmitter or RF receiver; (5) an optical transmitter or receiver; (6) a power amplifier; (7) a GPU; (8) a CPU; (9) a DSP; (10) an ASIC; (11) an APU; (12) an LED; (13) a laser diode; (14) a power electronic device, e.g. a power inverter or a power converter; (15) a photonic devices, (16) a propulsion system; (17) a solar array, e.g. for a micro satellite; (18) a radiator, e.g. for a micro satellite; (19) an engine of a micro drone; (20) a spacecraft component such as an SSPA; (21) a traveling wave tube amplifier; (22) a package that holds one or more of the devices of (1)-(21), and (23) a stack or plurality of stacks of devices sandwiched between separated heat transfer arrays or interleaved with multiple heat transfer arrays. 
     
     
       11. The system of  claim 5  wherein the heat transfer array comprises a plurality of adhered planar layers of at least one material where successive layers can be distinguished by stair-stepped configurations and wherein layers extend laterally in a cross-sectional dimension and a layer stacking axis is substantially perpendicular to a direction of fluid jetting. 
     
     
       12. The system of  claim 5  wherein the heat to be removed requires a heat flux, from at least a portion of the primary heat transfer region, selected from the group consisting of (i) >=200 W/cm 2 , (ii) >=400 W/cm 2  and (iii) >=800 W/cm 2 ). 
     
     
       13. The system of  claim 12  wherein the temperature of the surface or the plurality of separate surfaces of the heat source are to be held to a temperature selected from the group consisting of (i) <=100° C., (ii) <=80° C., and (iii <=65° C. 
     
     
       14. The system of  claim 12  wherein a variation in temperature over the surface or the plurality of separate surfaces of the heat source is to be held at a temperature selected from the group consisting of (i) <=20° C., (ii) <=15° C., and (iii) <=10° C. 
     
     
       15. The system of  claim 14  wherein a flow of the heat transfer fluid through the heat transfer array is selected from the group consisting of (i) <=2.0 L/min per 4 mm×4 mm area covered by the heat transfer array, (ii) <=1 L/min per 4 mm×4 mm area covered by the heat transfer array, and (iii) <=0.5 L/min per 4 mm×4 mm area covered by the heat transfer array. 
     
     
       16. The system of  claim 5  wherein at least a portion of the plurality of microjet structures provide flow paths with a cross-sectional dimension in the range selected from the group consisting of (1) 15 to 300 um and (2) 30-200 um. 
     
     
       17. The system of  claim 5  wherein at least a portion of the post jetting microchannels have a cross-sectional dimension in the range selected from the group consisting of (1) 15-300 um and (2) 30-150 um. 
     
     
       18. The system of  claim 5  wherein distal ends of the enclosing jetting channels of the plurality of microjet structures are spaced from the at least one surface of the primary heat exchange region by length in the range selected from the group consisting of (1) 15-200 um and (2) 30-100 um. 
     
     
       19. The system of  claim 5  wherein a first height of at least a plurality of post jetting microchannels is in the range selected from the group consisting of (1) 40 to 600 um and (2) 80-300 um, wherein the first height is measured along a portion of the microchannels that directs fluid flow in a direction substantially anti-parallel to a direction of flow of fluid through the jetting structures. 
     
     
       20. The system of  claim 5  wherein a height of at least a plurality of the jetting structures is in the range selected from the group consisting of (1) 300 um to 1 mm and (2) 400-800 um. 
     
     
       21. The system of  claim 5  wherein a height of at least a plurality of the microjet structures is selected from the group consisting of (1) 300 um to 2 mm and (2) 400-800 um, wherein a second height of at least a plurality of post jetting microchannels is selected from the group consisting of (1) 300-2000 um and (2) 600-2000 um, wherein the second height is measured along a portion of the microchannels that directs fluid flow in a direction substantially perpendicular to the direction of fluid flow through the jetting structures. 
     
     
       22. The system of  claim 5  wherein the at least one surface of the primary heat exchange region comprises a plurality of jetting well surfaces surrounded by jetting well walls having heights that extend from the at least one surface of the primary heat exchange region to a height that is above a height at which fluid exits the enclosing jetting channels of the plurality of the microjet structures. 
     
     
       23. The system of  claim 5  wherein the heat transfer array is configured to use a heat transfer fluid selected from the group consisting of: (1) a liquid, (2) water, and (3) a liquid that does not undergo a phase change during a process of cooling a semiconductor. 
     
     
       24. The system of  claim 5  wherein a filter is located in a position selected from the group consisting of: (1) along a flow path between the outlet and the pump, (2) along a flow path between the pump and the inlet, and (3) along a flow path between the pump and the heat exchanger. 
     
     
       25. The system of  claim 5  wherein the pump has a position selected from the group consisting of: (1) mounted to a header or manifold of the cold plate and (2) spaced from the cold plate. 
     
     
       26. The system of  claim 5  additionally comprising at least one temperature sensor and a control system having a functionality selected from the group consisting of: (1) turning on the pump when a detected temperature is greater than a high temperature set point and (2) turning off the pump when a detected temperature is less than a low temperature set point. 
     
     
       27. The system of  claim 5  wherein the system comprises at least two heat transfer arrays with a relationship selected from the group consisting of: (1) spaced from one another to remove heat from separated portions of a single integrated circuit and (2) spaced from one another to remove heat from two different integrated circuits. 
     
     
       28. The system of  claim 5  additionally comprising a pressure sensor to monitor fluid pressure in at least one flow path. 
     
     
       29. The system of  claim 5  wherein the micro cold plate comprises a single structure that provides both the inlet header or manifold and the outlet header or manifold. 
     
     
       30. The system of  claim 5  wherein the surface onto which jetting occurs is closer, in the jetting direction, to the heat source than are the plurality of post jetting microchannel flow paths. 
     
     
       31. The system of  claim 5  wherein each microjet structure provides a plurality of fins separated by fluid flow regions such that each microjet provides a plurality of contacts to the surface of the primary heat exchange region onto which jetting occurs. 
     
     
       32. The system of  claim 5  wherein each fin has an elongated cross-sectional configuration. 
     
     
       33. A thermal management system for a semiconductor device comprising:
 (1) at least one micro cold plate, comprising:
 (a) at least one fluid inlet header or manifold; 
 (b) at least one fluid outlet header or manifold; 
 (c) a hybrid microjet and microchannel heat transfer array, comprising:
 (I) a plurality of microjet structures for directing a heat transfer fluid from the at least one fluid inlet header or manifold onto at least one surface of a primary heat exchange region selected from the group consisting of:
 a. a surface of a heat source or a plurality of separated surfaces of a heat source: 
 b. at least one surface in proximity to one or more heat source surfaces wherein a separation distance between the at least one surface onto which jetting occurs and a surface or a plurality of separate surfaces of a heat source is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um; 
 c. at least one surface of a solid material separated from a surface or a plurality of separate surfaces of a heat source by a gap that is occupied by at least one highly conductive transfer material that may be a different solid, a semi-liquid, or a liquid wherein a thickness of the gap is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um); and 
 d. at least one surface of a solid that is in intimate contact with a surface or a plurality of separate surfaces of a heat source; and 
 
 (II) a plurality of post letting microchannel flow paths to direct the heat transfer fluid from the primary heat exchange region to the at least one outlet header or manifold, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the microchannel flow paths; 
 
 
 (2) at least one flow path to move heated fluid, directly or indirectly, from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; 
 (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and 
 (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate, 
 wherein the heat transfer array is configured to withdraw heat from a semiconductor device, 
 wherein the at least one surface of the primary heat exchange region comprises a plurality of jetting well surfaces with each jetting well surface surrounded by walls that direct fluid away from the jetting well surfaces into the microchannel flow paths, and 
 wherein each of the plurality of jetting well surfaces is configured to directly receive jetted fluid from a single microjet structure, 
 wherein the plurality of microjet structures have elongated cross-sectional configurations (i.e. in a plane perpendicular to a jetting direction) with a length to width aspect ratio selected from the group consisting of: (i) <=10 to 1, (ii) <=5 to 1, (iii) <=3 to 1, or (iv) <=2 to 1. 
 
     
     
       34. A thermal management system for a semiconductor device comprising:
 (1) at least one micro cold plate, comprising:
 (a) at least one fluid inlet header or manifold; 
 (b) at least one fluid outlet header or manifold; 
 (c) a hybrid microjet and microchannel heat transfer array, comprising:
 (I) a plurality of microjet structures for directing a heat transfer fluid from the at least one fluid inlet header or manifold onto at least one surface of a primary heat exchange region selected from the group consisting of:
 a. a surface of a heat source or a plurality of separated surfaces of a heat source; 
 b. at least one surface in proximity to one or more heat source surfaces wherein a separation distance between the at least one surface onto which jetting occurs and a surface or a plurality of separate surfaces of a heat source is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um; 
 c. at least one surface of a solid material separated from a surface or a plurality of separate surfaces of a heat source by a gap that is occupied by at least one highly conductive transfer material that may be a different solid, a semi-liquid, or a liquid wherein a thickness of the gap is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um); and 
 d. at least one surface of a solid that is in intimate contact with a surface or a plurality of separate surfaces of a heat source; and 
 
 (II) a plurality of post jetting microchannel flow paths to direct the heat transfer fluid from the primary heat exchange region to the at least one outlet header or manifold, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the microchannel flow paths; 
 
 
 (2) at least one flow path to move heated fluid, directly or indirectly, from the from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; 
 (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and 
 (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate, 
 wherein the heat transfer array is configured to withdraw heat from a semiconductor device, and 
 wherein the majority of the heat exchange from a solid to the fluid occurs via a surface of a first metal and wherein selected portions of the heat transfer array are formed from a second metal of higher thermal conductive than the first metal such that heat conductivity as a whole is improved relative to the heat conductivity if the second metal were replaced with the first metal. 
 
     
     
       35. A thermal management system for a semiconductor device comprising:
 (1) at least one micro cold plate, comprising:
 (a) at least one fluid inlet header or manifold; 
 (b) at least one fluid outlet header or manifold; 
 (c) a hybrid microjet and microchannel heat transfer array, comprising:
 (I) a plurality of microjet structures for directing a heat transfer fluid from the at least one fluid inlet header or manifold onto at least one surface of a primary heat exchange region selected from the group consisting of:
 a. a surface of a heat source or a plurality of separated surfaces of a heat source; 
 b. at least one surface in proximity to one or more heat source surfaces wherein a separation distance between the at least one surface onto which jetting occurs and a surface or a plurality of separate surfaces of a heat source is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um; 
 c. at least one surface of a solid material separated from a surface or a plurality of separate surfaces of a heat source by a gap that is occupied by at least one highly conductive transfer material that may be a different solid, a semi-liquid, or a liquid wherein a thickness of the gap is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um); and 
 d. at least one surface of a solid that is in intimate contact with a surface or a plurality of separate surfaces of a heat source; and 
 
 (II) a plurality of post jetting microchannel flow paths to direct the heat transfer fluid from the primary heat exchange region to the at least one outlet header or manifold, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the microchannel flow paths; 
 
 
 (2) at least one flow path to move heated fluid, directly or indirectly, from the from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; 
 (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and 
 (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate, 
 wherein the heat transfer array is configured to withdraw heat from a semiconductor device, and 
 wherein regions of the at least one surface of the primary heat exchange region onto which jetted fluid impinges are strengthened with a material different from that used to form the side walls of the jetting structures. 
 
     
     
       36. A thermal management system for a semiconductor device comprising:
 (1) at least one micro cold plate, comprising:
 (a) at least one fluid inlet header or manifold; 
 (b) at least one fluid outlet header or manifold; 
 (c) a hybrid microjet and microchannel heat transfer array, comprising:
 (I) a plurality of microjet structures for directing a heat transfer fluid from the at least one fluid inlet header or manifold onto at least one surface of a primary heat exchange region selected from the group consisting of:
 a. a surface of a heat source or a plurality of separated surfaces of a heat source; 
 b. at least one surface in proximity to one or more heat source surfaces wherein a separation distance between the at least one surface onto which jetting occurs and a surface or a plurality of separate surfaces of a heat source is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um; 
 c. at least one surface of a solid material separated from a surface or a plurality of separate surfaces of a heat source by a gap that is occupied by at least one highly conductive transfer material that may be a different solid, a semi-liquid, or a liquid wherein a thickness of the gap is selected from the group consisting of: (i) <=200 um, (ii) <=100 um, (iii) <=50 um, (iv) <=20 um, and (v) <=10 um); and 
 d. at least one surface of a solid that is in intimate contact with a surface or a plurality of separate surfaces of a heat source; and 
 
 (II) a plurality of post jetting microchannel flow paths to direct the heat transfer fluid from the primary heat exchange region to the at least one outlet header or manifold, wherein the at least one surface of the primary heat exchange region onto which jetting occurs is closer, in the jetting direction, to the surface or the plurality of separate surfaces of the heat source than are the microchannel flow paths; 
 
 
 (2) at least one flow path to move heated fluid, directly or indirectly, from the from the fluid outlet header or manifold of the at least one micro cold plate to a heat exchanger; 
 (3) at least one flow path to move cooled fluid, directly or indirectly, from the heat exchanger back into the inlet header or manifold of the at least one micro cold plate; and 
 (4) at least one pump functionally configured to direct the fluid through the at least one cold plate to the heat exchanger and back to the at least one cold plate, 
 wherein the heat transfer array is configured to withdraw heat from a semiconductor device, and 
 wherein the at least one surface of the primary heat exchange region comprises a plurality of jetting well surfaces surrounded by solid material that comprises a core material surrounded at least partially by a shell material wherein the core material has a higher thermal conductivity than does the shell material and also has a lower yield strength.